This invention relates to the control of windshield wipers, and, more particularly, to the control of such wipers when operating under variable load conditions.
Windshield wipers are commonly controlled by a motor that permits intermittent operation. Frequently, the rate of intermittent operation is adjustable. Under light moisture conditions, when it is necessary to operate the windshield wiper in order to maintain the windshield in a suitable condition for viewability, the motor is set for a relatively slow recurrence rate. If this is insufficient, and atmospheric distrubances are not serious enough to require continuous operation, the rate of intermittent operation is increased. This is done by manually adjusting the rate of intermittency.
Since atmospheric conditions can vary appreciably during the course of a drive, many motorists find it necessary to continually adjust the intermittent rate in order to maintain the desired cleaning effect.
Accordingly, it is an object of the invention to facilitate the control of windshield wipers. A related object is to facilitate the control of windshield wipers which are set for intermittent speed operation.
Another object of the invention is to avoid the need for frequent manual adjustments in the intermittent rate of windshield wiper operation in order to achieve the desired cleaning effect.
Still another object of the invention is to maintain the windshield wiper blade in a more satisfactory operating condition despite contrary changes in the surface that is being wiped.